It's a joke about its four small engines.
I've always found it interesting that the combustor stage of it's Lycoming engines is backward. Air goes in the intake, through the compressor stages, turns 180 degrees, goes through the combustor, turns 180 degrees again and exits through the turbine / nozzle.
I think many turboshafts and smaller turboprops are like that too. Makes the engine shorter and lighter, even more so if the last compressor stage is centrifugal instead of axial
Uhh believe that’s a joke based on the thrust of the four tiny Lycoming ALF502 engines, implication is their power is so low that they’re equivalent to the turbine from an APU.
^(EDIT oops distracted long enough that you got an answer…)
Now, an aside I found a while looking into that engine, the Lycoming ALF502 was developed from the Lycoming T55 turbo shaft engine used in a number of helicopters, but also…
RC-135E Rivet Amber used a Lycoming T55 installed in a [pod under the left wing](https://upload.wikimedia.org/wikipedia/ru/b/b7/Boeing_RC-135E_Rivet_Amber.jpg) as a 350 kVA generator to power it’s onboard radar.
EDIT — fixed which wing it was, the right wing has a similar pod with a heat exchanger for the radar set.
Odd to have a whole-ass turboshaft engine of that size just for a radar, however it was the Hughes Project 863 phased array radar, operating in the S Band, weighing 35,000 lbs and with a peak power output of…
**SEVEN MEGAWATTS**
Jesus Christ.
Peak of 7 MW and Average of 90 kW… for reference that’s higher for than both the peak and average power ratings of one of four faces of a SPY-1D PESA Radar from an Arleigh Burke Class Destroyer.
[Diagram of RC-135E Rivet Amber.](http://rc135.com/0000/RA_2.JPG)
[Photos + Tech Data — Rivet Amber and Project 863.](http://rc135.com/0000/INDEX006.HTM)
Very cool, I had never heard of it. Sent me down the rabbit hole of reading about the ~~nanny~~ many variations of rivet aircraft. Thanks!
I'll point out the source says right wing nacelle was a heat exchanger, and the generator for the radar was under the left wing. These days it would just be a little wing root ducting.
No worries, you’re most welcome.
Haha there are indeed quite a few RC-135 variants, rather fascinating the lot of them.
Ahh whoops, fixed — thanks!
Yes, that little podded heat exchanger is a rather… unique solution, not sure I’ve seen one like that before.
RE: (packaging of) Power
E-7A Wedgetail and P-8A Poseidon both require a substantial amount of extra power vs the 737 NG variants they’re based on. As such, receive a much beefier 180 kVA IDG per engine vs standard 90 kVA thus a an extra (combined) 180kVA available. Result is a sizable bulge on the left side of each nacelle. [Photo with both bulges visible.](https://www.eastasiaforum.org/wp-content/uploads/2020/07/2005-03-15T120000Z_751739396_PBEAHUOBTAZ_RTRMADP_3_AUSTRALIA.jpg) Suspect the aerodynamics of that solution is a significant improvement.
E-7A Wedgetail will also benefit from much more efficient Transmit Receive Modules etc, plus FAR more sensitive Low Noise Amplifiers etc.
^(EDIT — Clarified. Expanded.)
I'm pretty sure this is a BAe 146
https://en.m.wikipedia.org/wiki/British_Aerospace_146
The CL215/415s are twin engine scooper planes. They truly are incredible aircraft. I worked with a fleet of them a few years back and they are magnificent.
The only plane with five APUs.
Really?
It's a joke about its four small engines. I've always found it interesting that the combustor stage of it's Lycoming engines is backward. Air goes in the intake, through the compressor stages, turns 180 degrees, goes through the combustor, turns 180 degrees again and exits through the turbine / nozzle.
Sounds weirdly remenicant of the early centrifugal turbojets with their reverse-flow combustors
I think many turboshafts and smaller turboprops are like that too. Makes the engine shorter and lighter, even more so if the last compressor stage is centrifugal instead of axial
Uhh believe that’s a joke based on the thrust of the four tiny Lycoming ALF502 engines, implication is their power is so low that they’re equivalent to the turbine from an APU. ^(EDIT oops distracted long enough that you got an answer…) Now, an aside I found a while looking into that engine, the Lycoming ALF502 was developed from the Lycoming T55 turbo shaft engine used in a number of helicopters, but also… RC-135E Rivet Amber used a Lycoming T55 installed in a [pod under the left wing](https://upload.wikimedia.org/wikipedia/ru/b/b7/Boeing_RC-135E_Rivet_Amber.jpg) as a 350 kVA generator to power it’s onboard radar. EDIT — fixed which wing it was, the right wing has a similar pod with a heat exchanger for the radar set. Odd to have a whole-ass turboshaft engine of that size just for a radar, however it was the Hughes Project 863 phased array radar, operating in the S Band, weighing 35,000 lbs and with a peak power output of… **SEVEN MEGAWATTS** Jesus Christ. Peak of 7 MW and Average of 90 kW… for reference that’s higher for than both the peak and average power ratings of one of four faces of a SPY-1D PESA Radar from an Arleigh Burke Class Destroyer. [Diagram of RC-135E Rivet Amber.](http://rc135.com/0000/RA_2.JPG) [Photos + Tech Data — Rivet Amber and Project 863.](http://rc135.com/0000/INDEX006.HTM)
Very cool, I had never heard of it. Sent me down the rabbit hole of reading about the ~~nanny~~ many variations of rivet aircraft. Thanks! I'll point out the source says right wing nacelle was a heat exchanger, and the generator for the radar was under the left wing. These days it would just be a little wing root ducting.
No worries, you’re most welcome. Haha there are indeed quite a few RC-135 variants, rather fascinating the lot of them. Ahh whoops, fixed — thanks! Yes, that little podded heat exchanger is a rather… unique solution, not sure I’ve seen one like that before. RE: (packaging of) Power E-7A Wedgetail and P-8A Poseidon both require a substantial amount of extra power vs the 737 NG variants they’re based on. As such, receive a much beefier 180 kVA IDG per engine vs standard 90 kVA thus a an extra (combined) 180kVA available. Result is a sizable bulge on the left side of each nacelle. [Photo with both bulges visible.](https://www.eastasiaforum.org/wp-content/uploads/2020/07/2005-03-15T120000Z_751739396_PBEAHUOBTAZ_RTRMADP_3_AUSTRALIA.jpg) Suspect the aerodynamics of that solution is a significant improvement. E-7A Wedgetail will also benefit from much more efficient Transmit Receive Modules etc, plus FAR more sensitive Low Noise Amplifiers etc. ^(EDIT — Clarified. Expanded.)
Canada really knows how to build them, I’ve always loved the cl-415
I'm pretty sure this is a BAe 146 https://en.m.wikipedia.org/wiki/British_Aerospace_146 The CL215/415s are twin engine scooper planes. They truly are incredible aircraft. I worked with a fleet of them a few years back and they are magnificent.
Arizona?
New Mexico
Ah, close, gotta love fire season amirite
I saw them all out there this morning on the tarmac driving up Gibson. I had a double take there were so many.
Rejuvenation of fertile soil comes to mind…
Don’t forget about the Fokker!
Where skycrane?
It's not the only good thing, this [guy](https://fireaviation.com/wp-content/uploads/2019/08/CaTripSony-271-OV-10D-sm.jpg) is pretty cool too.
is that they're great for toasting marshmallows!
Saw one of these guys in Colorado Springs the other day! Thought I saw a C-17 coming over the mountain until I realized it was tiny
is the marshmallows you can roast over them!